Objective To investigate the effect of different concentration of propofol on cell viability in hippocampal neurons of fetal rats in vitro.Methods Primary cultured hippocampal neurons were prepared from the fetuses of Sprague-Dawley rats after 17 d-18 d of gestation,and cultured for 7 d,immunocytochemical method was used to identify the cultured neurons.① The neurons were randomly divided into 12 groups (n=5):control group (group C) received no treatment,in group D 0.1% dimethyl sulfoxide (DMSO) was added,in group P1-10 propofol was added at the final concentration of 0.01,0.1,0.5,1,5,10,50,100,150 μmol/L and 200 μmol/L respectively.The cells were selected after 24 h incubation for detection of the cell survival rate by cell viability[3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay].② The neurons were randomly divided into 7 groups(n=5):control group (group C) received no treatment,in group D 0.1% DMSO was added,in group PⅠ,Ⅱ,Ⅲ,v,v propofol was added at the final concentration of 0.1,1,10,100 μmol/L and 200 μmol/L respectively.The cells were selected after 24 h incubation for detection of the neuronal apoptosis by immunofluorescence staining and flow cytometry.Results ① There was no significantly difference in the cell survival rate between group C and D (P>0.05).Compared with group D,the cell survival rate was no significantly difference in group P1,2,5(P>0.05),the cell survival rate was significantly increased in group P3(102.2±2.7)%,P4(102.9±2.7)%(P<0.05) and that was significantly lower in group P6-10 in a concentration-dependent manner by (97.0±3.5)%,(90.1 ± 1.7)%,(79.8±0.9)%,(67.9± 1.1)%,(42.3±2.2)% respectively (P<0.05 or P<0.01).② There was no significantly difference in the neuronal apoptosis rate between group C and D (P>0.05).Compared with group D,the neuronal apoptosis rate was no significantly difference in group PⅠ (P>0.05),the neuronal apoptosis rate was significantly decreased in group PⅡ (P<0.05) and that was significantly higher in group PⅢ,Ⅳ,Ⅴ in a concentration-dependent manner by (8.2±0.8)%,(18.1±1.1)%,(29.1±2.1)% respectively(P<0.05 or P<0.01).Conclusions The effect of propofol on cell viability and apoptosis in hippocampal neurons was bidirectional,propofol at the concentration of 1 μmol/L can inhibit the apoptosis and improve the survival rate of neurons,while decrease the cell viability through promoting the cell apoptosis in a concentration-dependent manner at the concentration of 10,100 μmol/L and 200 μmol/L. Key words: Propofol; Hippocampal neuron; Cell viability; Apoptosis